The present invention relates to a transmitter of a tire condition monitoring apparatus that permits a driver in a vehicle passenger compartment to check the conditions of tires, such as the air pressure, and to a tire condition monitoring apparatus. More particularly, the present invention relates to a transmitter of a tire condition monitoring apparatus that can be identified as a data transmission source among a plurality of transmitters of the same type respectively provided in a plurality of tires, and to a tire condition monitoring apparatus using the transmitter.
Wireless tire condition monitoring apparatuses that allow a driver in a vehicle passenger compartment to check the conditions of vehicle tires have been used. One such monitoring apparatus includes transmitters, each of which is attached to one of the tires. Each transmitter detects condition, such as the pressure, of the associated tire, and wirelessly transmits data representing the detected tire conditions. A receiver for receiving the data that has been wirelessly transmitted from the transmitters is provided on the vehicle body.
The transmitters each transmit data representing a condition of the corresponding tire to the single receiver. When receiving data, the receiver must identify which one of the transmitters has sent the data. To enable the identification, a specific identification data (ID code) is given to each of the transmitters. Each transmitter transmits data on the conditions of the tire together with an ID code given to it. The receiver can therefore identify the transmitter as the transmission source on the basis of the ID code (refer to Japanese Laid-Open Patent Publication No. 2000-103209).
To enable the receiver to identify the transmission-source transmitter, it is necessary to register, in advance, in the receiver, the ID codes for the transmitters in the tires mounted on the vehicle. At the time of initial registration, there is also a need to relate the ID codes to the positions at which the tires with the transmitters having the ID codes are mounted. Therefore, initial registration must be performed always when a new tire is mounted on the vehicle or when the mounted positions of the tires on the vehicle are changed. The process of manually performing such initial registration is troublesome and time-consuming.